Reconstruction of the charge collection probability in a CIGS solar cell by the regularization method

We introduce a new nondestructive and parameter-independent optoelectronic method to analyze the internal quantum efficiency (IQE) data that are obtained on a copper indium gallium diselenide (CIGS) solar cells. This method directly reconstructs the distribution of the charge collection probability in the device by inverting the integral transform that connects charge collection probability to the measured IQE. This inversion is generally an ill-posed problem, but we obtain a stable solution using the Truncated Singular Value Decomposition (TSVD) regularization method. This procedure is used to analyze simulated and measured IQE data on CIGS solar cells.